Clean the wraps real good with denatured alcohol to remove any WD 40 or other oils or grease that might be on them. I usually scuff the surface with a grey scotch brite pad or 600 wet and dry sandpaper to create a good surface for the new coat of flexcoat. 99% of the time the new coat will go on with no problems. Once in a while it will bead up for some unknown reason and won't want to smooth out. If that happens you have to wipe off everything then after everything dries you can coat the wraps with permagloss and after that dries the flexcoat will usually go on with no more problems.